The short answer
Not properly. Lead flashing has to be dressed onto dry surfaces and fixed into dry mortar joints, and the pointing that holds it needs dry conditions to set. In wet weather a roofer can make a leak safe with a temporary cover and then return for the permanent repair when the roof and walls have dried out.
A leak does not wait for good weather, but a lasting lead repair does. Know what to do on the wet day and what to leave for the dry one.
Why rain and lead do not mix
Lead is fixed against brickwork, stone or timber, and each of those holds water. Dress a flashing over a damp surface and the moisture stays trapped underneath. It can corrode the underside of the lead and rot the timber beneath. Our answer on underside corrosion of lead covers what trapped damp does over the years.
What about the working conditions?
A wet roof is a slippery roof. Slates and tiles lose grip, lead sheet gets slick, and wind-driven rain makes it hard to hold a large piece in place while it is shaped. A showery day is still a poor day to dress lead on a pitched roof, because the surface never dries between bursts.
Wet weather affects the materials too. Mortar for the chase has to be mixed and placed in conditions that let it cure. A sudden shower washes fresh mortar out of the joint before it has taken hold, leaving a gap exactly where the lead needed support.
None of this is fussiness. It decides whether the lead lasts as long as it should, and whether the repair needs doing a second time within a couple of winters.
What can be done on a wet day
When water is coming in, the job is to stop it. A roofer can fit a temporary cover over the failed area, such as a sheet fixed over the flashing, or a weighted membrane laid across a chimney apron. That is a make-safe, not a repair, and we describe it that way.
Is a temporary cover a proper fix?
No. It buys time. Wind can lift it, and water can still track under the edges, so it needs checking after storms. If you have a leak, move belongings, catch the water in a bucket and photograph the ceiling stain. The pictures also help if you decide to claim, as our answer on home insurance for lead flashing explains.
Inside the house, a bulging ceiling can be eased by piercing a small hole so water drains into a bucket. Stand clear of the spot while you do it, and leave anything electrical alone.
Our order of work on a wet day is simple. We cover the leak and protect the building, then plan the lead repair for a dry spell once the roof can be reached safely. That order protects the ceiling now and the lead later.
What waits for dry conditions
Fitting new lead, re-dressing existing flashings, chasing a slot into a wall, wedging the lead and pointing the joint all need dry surfaces. Pointing is the mortar or sealant that closes the chase after the lead is wedged in. It must set properly, and a damp joint cannot do that.
How long should we wait?
That depends on the roof and the walls. A south-facing slope dries quickly. A shaded stack on a north slope, or a stone wall that has soaked up days of rain, takes longer. We judge by touching and looking at the surface rather than by the forecast alone, and we will not cut a chase in a wall that is still wet through.
Hot dry weather has its own problems, since mortar that dries too quickly weakens. A mild, settled spell suits lead work best.
The date of the work is agreed with you, and if rain stops a day, the job moves and you hear what happens next. Once we have surveyed the roof, you get a single written price for the work. Our answer on what leadwork is covers the stages if you want to follow them.
Planning a repair around the weather
The best time for a planned lead job is a settled spell in spring or early autumn, when roofs are dry and daylight is long. Emergencies do not choose their season, so the make-safe and the permanent repair often happen as two separate visits.
Should you wait for summer?
Not if water is entering the house. Damp that sits in plaster and timber causes more harm than a few weeks spent waiting for the right weather. Make safe now, repair properly when the roof is dry, and leave the temporary cover in place until then.
The survey comes first, and the pictures it produces show you the fault on your own flashing. If the repair has to wait for dry conditions, the price still follows what was found, not what the weather did that week.
Where scaffold is needed, the highway licence is handled jointly with the scaffolder, and that can add waiting time before the work starts. Our lead work page sets out the repairs we handle. A photo of the leak and the area around it is enough for us to say what can be done now and what should wait.
If a downpour is forecast and the cover is already on, there is nothing to rush.
More on working in wet weather
Can lead be fitted in light drizzle?
Light rain still wets the surfaces the lead sits on, and it makes the roof slippery. We prefer to wait for the surfaces to dry. A short pause costs far less than a flashing that traps damp under the lead and fails early, needing a second visit.
Will a temporary repair last until the weather improves?
A well-fixed temporary cover usually lasts through a spell of bad weather, but it is not designed to last for months. Wind can lift it, so it is checked after storms, and the permanent repair is arranged as soon as the slope can be worked on safely.
The full picture: Lead work in Taunton ยท More short answers